[Evaluation of digital technology for orthognathic surgery in 25 patients]

To use three-dimensional reconstruction measurement, preoperative diagnosis, surgical design, surgical simulation, guide plate production, navigation verification and effect evaluation of orthognathic surgery assisted by digital technology, in order to explore more scientific and reasonable programs and procedures of orthognathic surgery.

Twenty-five patients with congenital dental and maxillofacial deformity were selected as the experimental subjects, craniofacial spiral CT was conducted before surgery and CT data were imported into Mimics 20.0 software to establish a 3D head digital model. The bone landmarks in three-dimensional reconstruction digital model were selected, measured, analyzed and diagnosed, and the design of the surgical plan and the production of the guide plates were performed. Surgical navigation system was used to confirm the maxillary position, verify the bone retention and guide precise bone grinding during operation. Craniofacial spiral CT was conducted 1 week after surgery for postoperative validation of the surgical design protocol. Statistical analysis was performed using SPSS 24.0 software package.

All 25 patients were operated according to the digital orthognathic surgery design and procedure.There were no significant differences in X, Y and Z three-dimensional directions in 10 actual landmarks between the postoperative actual head model and the preoperative predictive head model（P>0.05）.

Orthognathic surgery assisted by digital technology has the advantages of precision and minimal invasiveness.